JANUS has always been intended to operate in several frequency bands. The primary band has long been settled (though not without treading on a few people's toes along the way). It has been difficult to get anyone to push for additional bands, possibly because whatever band is suggested will conflict with some system or another. Now we have the NATO Industrial Advisory Group formed, one of their tasks is to make recommendations for additional bands, within a year from now.
So, if you have ideas and want to weigh in on the issue, get posting and let us know!